Walt Disney World is constantly changing. At times
new attractions come in, while at the same time old attractions
disappear. Tomorrowland holds a nice little nod to both the old and
new at the exit of Space Mountain. Just after exiting your rocket
and before getting on the moving walkway, you will notice a robot on
the lefthand side sitting at a desk. On the far left side of the
desk you can find the following image:

As you can see, there are open and closed sectors
featured here, but what do the letters found there mean exactly? The
attraction, which went through a refurbishment in 2009 added these
letters which symbolize different attractions. The letters, along
with their meaning, can be found below: